Seve Ballesteros, the most flamboyant golfer of his generation, confirmed yesterday that he had a brain tumour, but said that he was ready to “confront the most difficult match of his life”.

It is not yet known if the tumour is malignant, and Ballesteros, 51, will undergo a biopsy tomorrow. The Spaniard, who won five majors including three Opens, has been in hospital in Madrid since collapsing a week ago.

In a statement issued by the Hospital de la Paz yesterday he said: “After being able to notify my three children personally and their mother I can inform you of my illness.

“After exhaustive checks at the hospital they have detected a brain tumour. During my career I was one of the best at getting around obstacles on golf courses. Now I want to be the best at confronting the most difficult match of my life with all my strength.

“I have always felt solidarity with those facing illnesses, many who were much older than me. I want to recall their bravery, belief, calmness, confidence and great mental strength. We need to confront these situations, however difficult they may be.”

Ballesteros asked for his privacy to be respected, but said: “I want to thank from the very bottom of my heart all those people interested in my state of health with many different types of support.”

There has been speculation about Ballesteros’s health for several months. When announcing his retirement at the Open in Carnoustie last year, he was forced to deny that he suffered from bouts of depression.

The golfer, who is separated from his wife Carmen BotÍn, also rejected reports that he had tried to commit suicide with an overdose of pills after the death of his girlfriend, Fatima Garlaza, in a car crash. He said that he had, in fact, been admitted to hospital with a heart problem, with tests discovering an irregular heartbeat.

Ballesteros was admitted to hospital after suffering dizziness and a brief loss of consciousness at Madrid airport a week ago. He had seemed to be making a recovery last Thursday when he released a statement through his family, saying: “Thank you for your concern for my health and for your message of support. I would like to inform you that I feel well.”

However, his condition deteriorated on Friday, and hospital officials released a statement then saying that Ballestoros had suffered “a partial epileptic fit”. He left intensive care over the weekend and doctors said that he was in a stable condition.

Ballesteros won 87 titles during his career, including the Open in 1979, 1984 and 1988 and the Masters in 1980 and 1983. He also played an inspirational role in the Ryder Cup, winning 20 points from 37 matches, as well as captaining Europe to victory at Valderrama in 1997.

His brilliant strokeplay thrilled the crowds – none more so than a shot from an overspill car park next to the 16th fairway at Royal Lytham & St Annes on his way to victory at the Open in 1979.

José Maria Olazábal, who visited Ballesteros after playing at the Madrid Masters yesterday, said: “I saw Seve looking very well. We were speaking for quite a little while. I wish him a prompt recovery.”